I think the point is having a proper display option. Most photographers shoot and edit in RAW, but the final product is almost always displayed as a jpg. I don't think this is meant to eliminate gif entirely, just limit it to the areas it belongs, like editing as you pointed out. The only issue I see is that there needs to be an easy option to download the original pre-converted file.
But GIF is a terrible intermediate format. It's only 'lossless' in the sense that there's no advanced compression going on. But since it can only produce 256 colors gifs tend to be extremely lossy for video-like formats, often producing awful color banding.
Sure, if you're doing things with a very small color palette like pixel art or software tutorials then the current gif is fine for your needs, but gifs are increasingly used for video which typically has a huge color range in each frame, and we need something different for these cases.
